Up to 100,000 Californians have been infected with a potentially fatal disease

without even knowing it.

Chagas disease, caused by a parasite that lives inside so-called "kissing bugs," has been reported in California and 29 other U.S. states, according to the Los Angeles Times.

The illness, which has potentially infected between 70,000 and 100,000 California residents, lies dormant for years, only making itself known when victims suffer serious cardiac issues, including heart attacks or strokes.